Composite length of pile fabric sheet material



H. GIRARD 3,426,363 COMPOSITE LENGTH OF FILE FABRIC SHEET MATERIAL Feb.11, 1969 Filed Feb. 17, 1965 I N VENTOR. LAURENT H GIRARD ATTORNEYSUnited States Patent 3,426,363 COMPOSITE LENGTH OF PILE FABRIC SHEETMATERIAL Laurent H. Girard, Bedford, N.H., assignor to American VelcroInc., a corporation of New Hampshire Filed Feb. 17, 1965, Ser. No.433,341

U.S. Cl. 2338 6 Claims Int. Cl. A41f 3/62, 9/00, /00

This invention relates to a method of joining together lengths of sheetmaterial, at least one of which is pile fabric sheet material of thetype having a pile surface of hooking elements extending from onesurface, and to the product resulting therefrom.

The pile fabric of this invention is generally described in U.S. PatentNo. 3,009,235. Basically the pile fabric sheet material consists of abase of sheet material which has a surface defined by hooking elementssecured thereto in positions extending generally vertically from onesurface of the base of sheet material to which they are secured. Thehooking elements can be formed from a flexible resilient material intoeither hooks or loops of the type characterized by the property that bypressing of a surface defined by said hooks in face-to-face adhesiverelation with a surface defined by said loops will result in a largenumber of hooks engaging a large number of loops to secure the membersin face-to-face relation.

In the manufacture and marketing of this type of pile fabric, it isoften desirable and essential that two lengths of pile fabric be joinedtogether lengthwise so as to form a more extended length of one type ofhooking element or a composite structure of the two types of hookingelements. Many attempts have heretofore been made to join this pilefabric together without a break in the continuous pile surface formed oneach of the two joined elements. Various types of butt seams have beenattempted and several differently configured elements have been fixed tothe abutting lengths of pile fabric for the purpose of effecting a buttseam therebetween without a break in the pile surface of the joinedelements; none have been accepted as satisfactory. Obviously a lap seamcould not be effected between the two lengths. The resilient hookingelements would not provide a flush surface between which a seam could beeffected and the bulk and resiliency of the hooking elements wouldresist attempts to compress the elements if an effort were made to forma flush lap seam therebetween; also, if a seam were effected in this waythe thickness of the seam would be objectionable in the finishedproduct. Similar problems attend attempts to join lengths of pileelements to a length of other sheet material.

I have found that these elements can easily be joined together by firstskiving or shaving the hooking elements down to the surface of the basematerial along a marginal end portion of a length of pile fabric so asto present a rather flat, smooth, marginal end portion which issubstantially free from the vertically extending hooking elements. Anadhesive is then applied over this fiat marginal end portion and it isthen overlapped with a second length of sheet material. When the secondlength of sheet material is of the type having one surface defined bysaid hooking elements with its hooking elements extending in the samegeneral direction as said first length, its back marginal end portionopposite to the surface on which the pile elements extend overlaps theflat marginal end portion. The two lengths positioned in this way arethen heat sealed together so as to define a unitary structure of twolengths of sheet material characterized by a substantially continuoussurface of hooking elements along one surface thereof.

The product formed is a composite length of two joined 3,426,363Patented Feb. 11, 1969 "ice lengths of sheet material, at least one ofwhich is the type having a surface of hooking elements as describedabove. The composite length is comprised of a first length of sheetmaterial having one surface defined by said hooking elements with a fiatmarginal end portion of said first length being substantially free ofsaid hooking elements. A second length of sheet material which also canhave one surface defined by said hooking elements with its hookingelements extending in the same general direction as said first lengthand its back marginal end portion opposite to the surface on which thepile elements extend overlapping the flat marginal end portion andjoined thereto in interfacial adhesive contact whereby the two lengthsare joined and define together a substantially continuous surface ofhooking elements. Of course, the hooking elements in the compositelength can be all hooks or all loops, or loops on one length and hookson the other length.

It has been found that the resulting product will withstand longitudinalseparation far better than any butt seam, and with a proper choice ofadhesive it will withstand the temperatures of cleaning and launderingof ordinary fabrics and in some special applications even will withstandautoclaving operations.

Although the method is particularly useful in manufacturing operationsfor making more extended lengths of pile fabric than are possible withweaving machines presently in use, it also has particularly novelapplications when a length containing books as the hooking elements anda length containing loops as the hooking elements are joined to form acomposite structure which is attachable to itself to form a closed loop.Simple attachment of a buckle to the end of one length gives this uniquestrap arrangement which has many holding and fastening uses. Similarproducts can be formed by combining alternate intermediate lengths ofhooks and loops in various sequences. Optionally, lengths of non-pilesheet material can be joined with a sheet of pile fabric according tothe invention Where required.

A preferred embodiment of the invention is described hereinbelow withreference to the drawing wherein:

FIG. 1 is a schematic of the successive steps in the continuousformation of joined lengths of pile fabric sheet material;

FIG. 2 is a section taken along lines 2-2 of FIG. 1;

FIG. 3 is a section taken along lines 33 of FIG. 1;

FIG. 4 is a section taken along lines 44 of FIG. 1;

FIG. 5 is a section taken along the seam between two lengths of sheetmaterial having hooks as hooking elements;

FIG. 6 is a section taken along lines 6-6 of FIG. 8 at the seam betweentwo lengths of sheet material one having loops as hooking elements andthe other having books as hooking elements;

FIG. 7 is a section taken along the seam between two lengths of sheetmaterial having loops as hooking elements; and

FIG. 8 is a composite buckle and strap device in which a length of sheetmaterial having hooks is joined to a length of material having loops.

As is known, the base material 10 is generally formed of a number offirmly woven weft threads and warp threads. The hooking elements 11,which can comprise either hooks 12 or loops, are generally formed fromsupplementary warp threads in the weaving operation. The base materialand the booking elements are also preferably formed from artificialmaterial such as nylon or some other material capable of being set byheat into a predetermined form. Once the hooking elements are formed inthe known manner, they may be fixed or stabilized to retain their shapeand position, generally vertically extending from the base material, byheat setting or by impregnation of the fabric by resinous plasticmaterials or both. Although description will be made with reference tothe woven base material construction it is intended that the basematerial can be a sheet of synthetic material, for example a resinousplastic material, and the selection of material used either for the basematerial or for the hooking elements can be varied in the many waysgenerally known in the art such as those described in the patentreferred to above.

In this preferred embodiment, however, the base material is a wovennylon fabric and the booking elements 11 are formed from nylon as asupplementary warp thread in the weaving operation. The hooking elementsare held in position by a polyurethane resin deposited at the base ofthe booking elements and impregnated into the interestices of the fabricby a solvent extraction process. This resin serves to hold the hookingelements in their upright position during the life of the fabricincluding laundering and drycleaning operations.

The schematic presentation in FIG. 1 is for a continuous operation ofjoining lengths of this type of pile fabric sheet material. As it is fedfrom an unwinding device 14 or directly from the weaving machine, alength of sheet material 15 is longitudinally passed through a series ofstations. At the first station 16 a marginal end portion 17 of atrailing end of a longitudinally advancing length of sheet material 15is positioned under a grinding wheel 18 to grind or skive the bookingelements from the marginal end portion. The grinding wheels usedconsisted of a vitrified bonded aluminum oxide or silicone carbide witha coarse to medium grain size abrasive which was run at surface speedsof 2750-6500 ft. per minute. By grinding the hooking elements to skivethem from the marginal end portion 17 so that substantially no elementswere extending vertically from the base material 10, a substantiallyfiat marginal end portion 17 was prepared on the trailing edge of thislength of sheet material. When the fabric has been impregnated with aresin for holding the pile elements upright, the flat marginal endportion often has a surface coating defined by the resin, even afterskiving. This is a factor to be considered in the selection of anadhesive as will be seen.

The length of sheet material was then passed to a second station 20where an adhesive deposit 21 was applied to the flat marginal endportion 17 by means of an adhesive applicator 22. The selection of theadhesive must involve a consideration of the materials at the interfacebetween the 'two lengths. In the example being described, the basematerial is nylon and the surface of the base material in back of thatfrom which the pile elements extend is essentially a nylon surface. Thebase material was impregnated with a polyurethane resin to hold the pileelements upright and after skiving the flat marginal end portion 17 issubstantially defined by this resin. Thus, an adhesive seal must beeffected between a nylon and a polyurethane surface. One adhesive whichcan effect the desired bond is a synthetic rubber resin, solvent typeadhesive, Velcro- (tradename of American Velcro, Inc.), This adhesivecontains approximately 20-28% by weight solids. The solids are comprisedof 40-60% by weight butadiene acrylonitrile copolymer rubber and 60-40%by weight of a vinyl resin which is a copolymer of vinyl chloride andvinyl acetate. The solvent comprised approximately 5050% mixture ofacetone and methylethylketone. The ingredients were blended to form aliquid adhesive. The adhesive is applied to the skived marginal endportion 17 in liquid form and then is immediately passed to the nextstation in the operation.

This first adhesive is useful for most applications as it provides abond strength of about 160 pounds and has a melting temperature of about175 F. This strength and melting temperature permit its use in mostnormal applications as it will withstand all normal laundering and drycleaning operations. Another example of an adhesive which can be used inbonding the pile fabric described is a phenolic adhesive Cycleweld l-C-6tape (tradename of Chrysler Corporation, Chemical Division). Thisadhesive is in tape form of thicknesses of .0035 inch and when used inthis application should be used in double thickness. This secondadhesive gives higher bond strength in the order of 350 pounds and has amelting point of about 325 F. If the joined fabric is to be used in themedical field where the fabric might be subjected to an autoclavingoperation, the second adhesive should be used because of its highermelting point.

With the adhesive 21 applied to the skived end portion 17, the lengthsheet material is then transferred to a heat sealing station 23. At theheat sealing station the leading marginal end portion 24 of a secondlength 25 of pile fabric is lapped over the adhesive coated skivedmarginal end portion 17 of the first length 15 of pile fabric so thatthe hooking elements of each length extend in the same direction. Theback marginal end portion opposite to surface from which the pileelements extend are placed in flush adhesive contact over the skivedmarginal end portion 17 with the adhesive 21 therebetween. A pair ofoppositely positioned heating elements 26 and 26' which are heated to atemperature of about 350 F. are brought together under air pressure ofabout 60 p.s.i. for approximately 10 seconds. The heating elements 26and 26' are then released and upon cooling a seam 27 has been effectedbetween the lengths 15 and 25 to form a unitary extended length of sheetmaterial containing hooking elemerits extending in the same directionwhich define a substantially continuous surface along one broad face ofthe joined lengths. By this method the portion of the joined length ofpile fabric at which the seam is formed is increased only by a thicknesssubstantially equal to the thickness of the base material, which ishardly noticeable, and will not interfere with any subsequent use of thematerial.

The product resulting from the operations described in FIGS. 1 to 4 isshown in FIG. 5 where the seam 27 effected a joining of two lengths ofsheet material containing hooks 28 as the hooking elements. However, asshown in FIG. 7 the same seam can be effected between two lengths ofsheet material containing loops 29 as hooking elements, or as shown inFIG. 6 a length containing hooks 30 can be joined to a length containingloops 31.

In FIG. 8 a particularly useful product, of which FIG. 6 is a section,is shown which was formed by providing a length of sheet material 32which has loops 31 extending from one broad face thereof and has abuckle 34, or any similar means which essentially provide a ring-likeelement through which the length can be inserted, attached to one end ofthis length 32. Attached to the opposite end of the length 32 in themanner of the invention is a shorter length 33 of fabric which has hooks30 vertically extending from one broad face as the hooking elements. Bythreading the end of this composite product defined by the fabriccontaining the hooks through the buckle so that the booking elementsextend on the outside of the loop formed by this threading operation,the end containing the hooks 30 can then be folded back against thelength 32 containing the loops 31 and can be pressed in face-to-facerelation with the loop surface so that a large number of hooks engage alarge number of loops to secure the members in face-to-face relation.Once attached in this manner, a closed loop is formed. This compositestrap can be used for many different purposes, such as an arm and legstrap for holding hospital patients, and many other uses are alsoimmediately suggested.

Although reference has been specifically made throughout to theattachment of lengths of pile fabric of the type having hooking elementsextending from one surface, and reference has only generally been madeto the attachment of a length of sheet material other than this typepile fabric to a length of this type pile fabric, it is intended thatthe method and product also offers novel features when attached to alength of leather, plastic or other nonpile type fabric.

I claim:

1. A composite length of at least two joined lengths of sheet material,at least one of which is a pile fabric sheet material of the type havinga surface of hooking elements secured thereto in positions extendinggenerally vertically from one surface of a base of sheet material towhich they are secured, said hooking elements being a flexible resilientmaterial of at least one of hooks and loops which are characterized bythe property that pressing of a surface defined by said hooks inface-to-face relation with a surface defined by said loops will resultin a large number of hooks engaging a large number of loops to securethe members in face-to-face relation comprising a first length of saidpile fabric sheet material having one surface substantially defined bysaid hooking elements, a flat marginal end portion of said first lengthbeing substantially free of said hooking elements, and a second lengthof sheet material having a marginal end portion overlapping the fiatmarginal end portion of the first sheet and joined thereto ininterfacial adhesive contact, whereby the two lengths are joined anddefine together a composite sheet of at least two lengths of sheetmaterial.

2. A composite length of at least two joined lengths of pile fabricsheet material of the type having a surface of hooking elements securedthereto in positions extending generally vertically from one surface ofa base of sheet material to which they are secured, said hookingelements being a flexible resilient material of at least one of hooksand loops which are characterized by the property that pressing of asurface defined by said hooks in face-to-face relation with a surfacedefined by said loops will result in a large number of hooks engaging alarge number of loops to secure the members in face-to-face relationcomprising a first length of said sheet material having one surfacesubstantially defined by said hooking elements, a flat marginal endportion of said first length being substantially free of said hookingelements, and a second length of said sheet material having one surfacedefined by said hooking elements and having its hooking elementsextending in the same general direction as said first length and itsback marginal end portion opposite to the surface on which the pileelements extend overlapping the flat marginal end portion, and joinedthereto in interfacial adhesive contact, whereby the two lengths arejoined and define together a substantially continuous surface of hookingelements.

3. A composite length of two joined lengths of sheet material accordingto claim 2 wherein the hooking elements on both lengths are hooks.

4. A composite length of two joined lengths of sheet material accordingto claim 2 wherein the hooking elements on both lengths are loops.

5. A composite length of two joined lengths of sheet material accordingto claim 2 wherein the hooking elements on one length are hooks and onthe other length are loops.

6. A composite length of at least two lengths of pile fabric sheetmaterial of the type having a surface of hooking elements securedthereto in positions extending generally vertically from one surface ofa base of sheet material to which they are secured, said hookingelements on one length being hooks and on the other length being loopswhich are characterized by the property that pressing of a surfacedefined by said hooks in face-to-face relation with a surface defined bysaid loops will result in a large number of hooks engaging a largenumber of loops to secure the members in face-to-face relationcomprising a first length of said sheet material having one surfacedefined by said hooking elements, a fiat marginal edge portion on oneend of said first length being substantially free of said hookingelements, a second length of said sheet material having one surfacedefined by said hooking elements having its hooking elements extendingin the same general direction as said first length and its back marginalend portion opposite to the surface on which the pile elements extendoverlapping the flat marginal end portion and joined thereto ininterfacial adhesive contact whereby the two lengths are joined anddefine together a substantially continuous surface of hooking elements,and a buckle attached to one end of the joined lengths through which theopposite end thereof can be inserted and folded back against itself withrespective surfaces of hooks and loops in engaging relationship to forma closed loop.

References Cited UNITED STATES PATENTS 1,842,746 1/ 1932 Chance 161-363,107,195 10/1963 Stegler et a1. 16136 1,962,780 6/1934 Luftig 23382,445,889 7/1948 Rossi et al 2-338 3,000,384 9/1961 Piers 132462,584,493 2/ 1952 Olsen 161-63 2,726,222 12/1955 Palmquist et al. 156157X 2,794,726 6/ 1957 Riedesel et a1 156-453 X FOREIGN PATENTS 651,58511/1962 Canada. 661,283 11/1951 Great Britain.

JORDIAN FRA'NKDIN, Primary Examiner. GEORGE V. LARKIN, AssistantExaminer.

6. A COMPOSITE LENGTH OF AT LEAST TWO LENGTHS OF PILE FABRIC SHEETMATERIAL OF THE TYPE HAVING A SURFACE OF HOOKING ELEMENTS SECUREDTHERETO IN POSITIONS EXTENDING GENERALLY VERTICALLY FROM ONE SURFACE OFA BASE OF SHEET MATERIAL TO WHICH THEY ARE SECURED, SAID HOOKINGELEMENTS ON ONE LENGTH BEING HOOKS AND ON THE OTHER LENGTH BEING LOOPSWHICH ARE CHARACTERIZED BY THE PROPERTY THAT PRESSING OF A SURFACEDEFINED BY SAID HOOKS IN FACE-TO-FACE RELATION WITH A SURFACE DEFINED BYSAID LOOPS WILL RESULT IN A LARGE NUMBER OF HOOKS ENGAGING A LARGENUMBER OF LOOPS TO SECURE THE MEMBERS IN FACE-TO-FACE RELATIONCOMPRISING A FIRST LENGTH OF SAID SHEET MATERIAL HAVING ONE SURFACEDEFINED BY SAID HOOKING ELEMENTS, A FLAT MARGINAL EDGE PORTION ON ONEEND OF SAID FIRST LENGTH BEING SUBSTANTIALLY FREE OF SAID HOOKINGELEMENTS, A SECOND LENGTH OF SAID SHEET MATERIAL HAVEING ONE SURFACEDEFINED BY SAID HOOKING ELEMENTS HAVING ITS HOOKING ELEMENTS EXTENDINGIN THE SAME GENERAL DIRECTION AS SAID FIRST LENGTH AND ITS BACK MARGINALEND PORTION OPPOSITE TO THE SURFACE ON WHICH THE PILE ELEMENTS EXTENDOVERLAPPING THE FLAT MARGINAL END PORTION AND JOINED THERETO ININTERFACIAL ADHESIVE CONTACT WHEREBY THE TWO LENGHTS ARE JOINED ANDDEFINE TOGETHER A SUBSTANTIALLY CONTINUOUS SURFACE OF HOOKING ELEMENTS,AND A BUCKLE ATTACHED TO ONE END OF THE JOINED LENGTHS THROUGH WHICH THEOPPOSITE END THEREOF CAN BE INSERTED AND FOLDED BACK AGAINST ITSELF WITHRESPECTIVE SURFACES OF HOOKS AND LOOPS IN ENGAGING RELATIONSHIP TO FORMA CLOSED LOOP.